Social networks like Facebook and LinkedIn can have positive and negative impacts on future job prospects for employers. Learn how to use your profile to your advantage.

Watch That Trumpet Volume Because online sites like Facebook, MySpace and blogs are open to anyone, they can provide an opportunity for people to present a certain image to specific employers, in addition to looking good to the whole professional world, notes Steven Rothberg, founder of CollegeRecruiter.com.

“Write about your passions and ideas, and employers who search Google or other sties can find your page and get to know you,” he advises. About 75 percent of employers admit to using Google to do background research on candidates, he notes, and a growing number are using the sites to include candidates rather than exclude them.

Although carefully crafted online identities can be useful in selling oneself to a potential employer or zipping through an annual HR review, it’s possible to be a bit too much like a used car salesman when it comes to promoting the better aspects of a personality.

For example, some LinkedIn users have groused about strangers who attempt to make a “connection” although they’ve never had any contact in the past.

Having an impressive roster of contacts is usually proof that a person can cultivate important professional relationships and nurture them through steady attention, but it’s much less praiseworthy when the cultivation involves only sending invites to strangers and hoping for the best.

“Most employers would be alarmed if I took out a billboard along the highway, showing off my photos and opinions,” she says. “But that’s just what a page in MySpace or Facebook is doing, and often, that’s how it’s viewed.”

People who are particularly open about discussing their personal lives may spark concern in managers who fret about their being equally candid about details on a project, client or other sensitive business matter.

“If I’m working for a company serving vendors who are careful about disclosure, I wouldn’t pick someone for a project who tells the world everything about themselves online,” says Gudaitis.

Individuals who show a high level of maturity and professionalism, however, can prevent this type of reaction by simply being selective about what kind of information they share.